Dr Anthony Haynes

Department of Chemistry

Reader in Inorganic Chemistry

Anthony Haynes
Profile picture of Anthony Haynes
a.haynes@sheffield.ac.uk
+44 114 222 9326

Full contact details

Dr Anthony Haynes
Department of Chemistry
Dainton Building
13 Brook Hill
Sheffield
S3 7HF
Profile

Dr. Haynes obtained his BSc from the University of Exeter in 1986. After obtaining his PhD from the University of Nottingham in 1989, he became a BP Chemicals Research Fellow at the University of Sheffield until 1993, when he was appointed the BP Chemicals Lecturer in Homogeneous Catalysis.

In 1998 he was appointed as Lecturer at the University of Sheffield. From this post he was promoted to Senior Lecturer (2002) and Reader (2009).

Qualifications
  • MRSC
  • CChem
Research interests

The Haynes group investigates mechanistic aspects of homogeneous transition metal catalysed reactions, particularly industrially important processes such as methanol carbonylation and alkene hydroformylation. Synthetic, spectroscopic, kinetic and computational methods are used to study the structure and reactivity of organometallic complexes and their roles in catalysis.

Mechanisms of rhodium and iridium catalysed methanol carbonylation

The catalytic carbonylation of methanol to acetic acid is one of the most significant industrial applications of homogeneous transition metal catalysis. We have a long-standing research collaboration with BP Chemicals, who operate methanol carbonylation plants worldwide, and introduced a new process(Cativa TM) in 1995 that uses a promoted iridium/iodide catalyst. Highlights of our mechanistic studies include the first spectroscopic detection of a highly reactive Rh-methyl intermediate in the rhodium-catalysed process[1] and elucidation of the role of promoters in the iridium-based system.[2] We recently showed that the rate of migratory CO insertion in [Ir(CO)2I3Me]- is dramatically increased by isomerisation to place a CO ligand trans to methyl.[3]

Ligand effects on oxidative addition and migratory CO insertion

We are interested in how the rates of key steps in catalytic cycles can be influenced by the electronic and steric properties of "spectator" ligands, e.g. phosphines, imines and N-heterocyclic carbenes. Strongly donating ligands tend to promote oxidative addition and retard migratory CO insertion, whereas sterically bulky ligands tend to have the opposite effects on these steps.[4] In a recent study of the mechanism of rhodium/xantphos-catalysed methanol carbonylation it was found that the key intermediates contained xantphos coordinated as a tridentate "pincer" ligand and the nucleophilicity of the metal centre is enhanced by a Rh---O interaction.[5]

Computational studies

Our experimental studies are complimented by theoretical calculations, carried out in collaboration with Dr. Anthony Meijer in this department. We are interested in modelling trends in organometallic reactivity and spectroscopic properties, e.g. vibrational spectra of metal carbonyl complexes.

Facilities

The department is well-equipped with modern instrumentation for NMR spectroscopy, X-ray crystallography, mass-spectrometry and chromatography. In addition, the group has dedicated FTIR instruments for kinetic measurements, including high pressure and stopped-flow IR cells.

References

1. (a) JACS, 1991, 113, 8567; (b) JACS, 1993, 115, 4093.
2. JACS, 2004, 126, 2847.
3. Inorg. Chem., 2009, 48, 28
4. (a) JACS, 2002, 124, 13597; (b) Organometallics, 2003, 22, 1047; (c) Organometallics, 2003, 22, 4451.
5. Organometallics, 2011, 30, 6166.

Publications

Journal articles

Chapters

Conference proceedings papers

  • Cavallo L & Haynes A (2002) Steric and electronic effects in the rhodium-catalyzed carbonylation reactions. Abstr Pap Am Chem Soc, Vol. 224 (pp U734-U734) RIS download Bibtex download
  • Graziani M & Rao CNR (1993) Advances in Catalyst Design. Advances in Catalyst Design RIS download Bibtex download
  • Norton JR, Bender BR, Wiser D, Haynes A, Poliakoff M & Turner JJ (1989) Os2(CO)8, an apparent intermediate in the olefin and acetylene exchange-reactions of diosmacyclobutanes. Abstr Pap Am Chem Soc, Vol. 198 (pp 329-INOR) RIS download Bibtex download

Patents

  • Haynes A, Law DJ, Miller A, Morris GE, Payne MJ & JSunley JG (2005) Catalyst and Process for the Production of Acetic Acid. WO2005009939 Appl. 19 Apr 2024. RIS download Bibtex download

Preprints

Teaching interests

Transition Metal Chemistry; Homogeneous Catalysis

Teaching activities

Undergraduate and postgraduate taught modules

  • Hydrogen and the s- and p-block elements (Level 1)
    This segment introduces key concepts regarding the structures and properties of the s- and p-block elements.
  • Reactivity and mechanisms of d-block complexes (Level 2)
    This course describes and explains the reaction mechanisms of transition metal complexes.
  • Organometallic Chemistry 1: longitudinal ligands (Level 3)
    This segment deals with the synthesis, structure, bonding and reactivity of transition metal complexes containing metal-carbon σ-bonds. It introduces the role of these complexes in catalytic reactions.
  • Homogeneous Catalysis (Level 4)
    This course describes the chemical basis behind some economically important industrial processes which use homogeneous transition metal catalysts to manufacture important products such as solvents, pharmaceuticals, polymers and detergents.

Support Teaching:

  • Tutorials: Level 1 General Chemistry.
  • Tutorials: Level 2 Inorganic Chemistry.
  • Skills for Success: Database Project.
  • Level 3 Literature Review

Laboratory Teaching:

  • Level 4 Research Project